Book Image

PostgreSQL High Availability Cookbook - Second Edition

By : Shaun Thomas
Book Image

PostgreSQL High Availability Cookbook - Second Edition

By: Shaun Thomas

Overview of this book

Databases are nothing without the data they store. In the event of a failure - catastrophic or otherwise - immediate recovery is essential. By carefully combining multiple servers, it’s even possible to hide the fact a failure occurred at all. From hardware selection to software stacks and horizontal scalability, this book will help you build a versatile PostgreSQL cluster that will survive crashes, resist data corruption, and grow smoothly with customer demand. It all begins with hardware selection for the skeleton of an efficient PostgreSQL database cluster. Then it’s on to preventing downtime as well as troubleshooting some real life problems that administrators commonly face. Next, we add database monitoring to the stack, using collectd, Nagios, and Graphite. And no stack is complete without replication using multiple internal and external tools, including the newly released pglogical extension. Pacemaker or Raft consensus tools are the final piece to grant the cluster the ability to heal itself. We even round off by tackling the complex problem of data scalability. This book exploits many new features introduced in PostgreSQL 9.6 to make the database more efficient and adaptive, and most importantly, keep it running.
Table of Contents (18 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback

Adding XFS to cluster management

Next in our list of resources to manage with Pacemaker is the filesystem. As with LVM and DRBD, Pacemaker needs the ability to start and stop the resource arbitrarily to clear locks or enable activation. In addition, filesystems are somewhat more complex than LVM, simply due to the number of necessary parameters required to use them.

In order for Pacemaker to manage a filesystem, we need to tell it about the device it's mounting, which directory the mount should target, the type of filesystem, and any extra options we want to use. While DRBD and LVM encode metadata within reserved storage areas on the device, filesystem mounts require explicit parameters.

This recipe will explain the steps necessary to manage our XFS filesystem with Pacemaker.

Getting ready

As we're continuing to configure Pacemaker, make sure you've followed all the previous recipes.

How to do it...

Perform these steps on any Pacemaker node as the root user:

  1. Export our list of XFS mount options...